Thread-cutting mechanism



Sept. 24, 1929.

J. M. BENJAMIN THREAD CUTTING MECHANISM Original Filed Oct. 28, 1920 4Sheets-Sheet 1 Sept. 24, 1929. J. M. BENJAMIN 1,729,241

THREAD CUTTING MECHANISM Original Filed Oct; 28 1920 4 Sheets-Sheet 2Sept. 24, 1929. J. M. BENJAMIN THREAD CUTTING MECHANISM Original FiledOct. 28. 1920v Sheets-Sheet 5 Sept. 24, 1929. .1. M. BENJAMIN 1,729,241

' THREAD CUTTING MECHANISM I Orglginal Filed Oct. 28, 1920 4Sheets-Sheet 4 Patented Sept. 24, 1929 UNITED STATES PATENT OFFICE JOHNBENJAMIN, F BEVERLY, MASSACHUSETTS, ASSIGNOR T0 UNITED SHOE MACHINERYCORPORATION, OF PATERSON, NEVJ' JERSEY, A CORPORATION OF NEW' JERSEYTHREAD-CUTTING MECHANISM- Application fil-ed October 28, 1920, SerialThis invention relates to machines for sewing together sections of sheetmaterial and, more particularly, to a thread cutting mechanism forsevering the thread after the completion of a seam.

The objects of the invention are to improve the construction and mode ofoperation of thread cutting mechanisms for machines of this class, andto produce a thread cutting mechanism which is simple in construction,reliable in operation, and which will operate automatically to sever thethread after the completion of a seam.

The invention is illustrated in the present application as embodied inmechanism arranged to sever the thread between articles or sections ofmaterial successively stitched upon the machine. It is to be understood,however, that the invention is not limited to this particular mode ofoperation, but certain features thereof may be embodied in mechanismsoperating to sever the thread between the stitch forming devices and theWork.

An important feature of the present invention consists in the provisionof means for moving the thread cutting device in the direction of feedwith the work while said device is in operation. In the presentconstruction the thread cutting device, when thrown into operation, isgiven several thread cutting movements and the movement of said devicein the direction of feed with the work practically insures the severingof the thread before said device is thrown out of operation.

The thread cutting device of the present machine is mounted for lateralor horizontal movements on a suitable support, and an- 40 other featureof the invention consists in the provision of mechanism for actuatingthe thread cutting device which is thrown into and out of operation bythe lateral movement of the support. The movements of the support areproduced and controlled by a work carrier during the movement of thecarrier through the machine. In the present embodiment of the inventionthe movement of the support not only throws the actuating mechanism forthe cutting de No. 420,103. Renewed February 14, 1925;.

vice into operation, but also carries the thread cutting device fromoperative to inoperative position with relation to the thread to besevered. The above feature makes for simplicity in the construction andfor lightness and easy running of the parts and enables the threadcutting device to be moved into operative position and to be thrown intooperation in a certain and reliable manner with the expenditure of verylittle force or power.

The invention embodies various other important features, constructions,and combination of parts hereinafter described and particularly pointedout in the claims, the advantages of which will be readily understoodand appreciated by those skilled in the art. r

The invention will be clearly understood from the accompanying drawingsillustrating the invention in its preferred form, and the followingdetailed description of the constructions therein shown.

In the drawings Fig. 1 is a view in front elevation of a machineembodying the invention; Fig. 2 is a view in horizontal section of aport-ion of the machine; Fig. 3 is a detail View in side elevation,looking from the left and illustrating the thread severing mechanism andcertain associated parts; Fig. 4 is a view in side elevation, lookingfrom the right, of the mechanism shown in Fig. 3; Fig. 5 is a view infront elevation illustrating certain of the parts shown in Figs. 8 and4; Fig. 6 is an underside plan view of certain parts, of the machine;Fig. 7 is an underside plan view illustrating particularly the threadsevering mechanisms; Fig. 8 is a view similar to Fig. 7 illustratingcertain of the parts in different positions; and Figs. 9 and 10 aredetail views illustrating respectively different parts of the mechanismshown in Figs. 7 and 8 detached from the machine.

The machine illustrated in the drawings has the same construction,arrangement and mode of operation of parts as the machine illustratedand described in the application of Benjamin F. Mayo, Serial No.368,025, filed March 23, 1920. The machine is especially designed to beemployed in sewing a seam along the backedges of the two parts of anupper generally known as the quarters to attach the same together. Bymaking certain relatively slight changes, however, the machine may befitted for sewing other seams.

The sewing mechanism of the machine is of well-known construction, andcomprises a vertically reciprocating straight-eyed needle 2, a presserfoot 4 and a feed dog 6. All of these parts are actuated from a mainshaft 8. The main shaft 8 is driven by means of a pulley 1O looselymounted on the shaft and a belt 12 passing about the pulley and about apulley 14 secured to a driving shaft I To enable the main shaft 8 to bestarted and stopped at suitable times, a friction hand arm of the lever18 is held in its rearward position during the sewing operation by theengagement of a spring actuated latch 22 pivoted on the lever with ashoulder 24 formed on an arm on the frame of the machine. After thecompletion of the sewing operation the latch 22 is thrown out ofengagement with the shoulder 24 and the left hand arm of the lever 18 isswung forwardly to cause the disengagement of the clutch by the actionof a suitable spring.

In the present machine a series of work clamping carriers is provided,each carrier being constructed to hold two parts of an upper to be sewntogether. Each of these carriers comprises a lower clamping plate 26 andan upper clamping plate 28 pivoted to the lower clamping plate by meansof a pivot pin 30 and normally held by the force of gravity in closedrelation to the lower clamping plate. The carriers illustrated in thedrawings are especially constructed for use in sewing quarters, and areprovided with gage devices to locate the parts in proper positionbetween the clamping plates. When the quarters are in place between thetwo clamping plates and the upper clamping plate is closed, the rearmargins of the quarters project uniformly beyond the clamping plateswhich conform to the curve of the quarters as clearly shown in Fig. 2.

The carriers of the present machine lie upon and are movable over theupper surface of a work table 32 and are moved over the table to carrythem in succession through the machine, the carriers being held on thetable merely by the action of gravity. l/Vhen the work is applied to acarrier the carrier is located at the front of the machine in what willbe termed, for convenience, work receiv ing position, the upper clampingplate then being open to receive the parts of the upper. After the workhas been placed in a carrier, the carrier is movedfrom work receivingposition past the sewing mechanism, guiding devices for the carriercausing the carrier to move in a predetermined path during the sewingoperation. After a seam is completed the carrier is moved back in twostages to work receiving position. Upon the completion of each scam, thesewing mechanism is stopped and the carriers come to rest and remainstationary until thenext operation.

The machine illustrated is provided with three work carriers which, whenthe machine is stopped after the completion of the sewing of a seam,occupy respectively the positions of the carriers A, B, and C, shown inFig. 2.

The carrier A is illustrated in this figure in work receiving position,the carrier B in the position which each of the carriers assume after aseam is completed through the parts of the upper carried thereby, andthe carrier C in the position which each of the carriers assume afterthe first stage in the bringing of the carrier back to work receivingposition.

Vi hen in work receiving position the cari'iers 11 f the table 32, anextension being formed on the table to assist in supporting thecarriers, and a. pair of pins 34 mounted on the lower clan'iping plateare engaged in a guiding groove or slot 36 1n said table.

The upper clamping plate is then held in open position by the engagementof a stationary cam plate 38 with a projection 40'on the upper clampingplate. When the parts of the upper have been placed on the carrier thecarrier is released and is then moved from work receiving positiontoward the sewing mecha 'nism by means of a radial projection or armformed on a rotary disk 44 and arranged to engage one of the pins 34.The disk 44 is rotated to move the carrier from work receiving positionupon the release of the carrier by a suitable frictionally actingdriving mechanism. When a carrier has been moved into work receivingposition, the arm 42is engaged with a rearward or left hand pin in theguidim slot 36, as shown in Fig. 2, and the carrier and the disk 44 arethen held from movement by the engagement of the forward pin 34 with theupper end of a vertically movable rod 46. To the lower end of the rod 46is connected an actuating lever 48 which is norm ally held in elevatedposition by a spring 50. Then the two parts of the upper have beenplaced in the work carrier, the operator actu ates the lever 48 todepress the pin 46 and thereby release the carrier. As the carrier isthus released the disk 44 starts to rotate and the carrier is moved fromwork receiving po* sition toward the stitch forming mechanism by theaction of the arm 42. The initial movement of the carrier from workreceiving posis tion carries the pro ection 40 out of engagement withthe cam plate 38 and the upper clamping plate is then closed on the workby the action of gravity.

The carrier is guided during its movement from work receiving positiontoward the sewing mechanism by the engagement of the pins 34 in theguide slot 36. The movement of the carrier produced by the disk 44carries the carrier over a sectional belt mounted on shafts 52 and 5 1which feeds the carrier through its frictional engagement with the lowerclamping plate. The guiding groove 86 terminates some distance forwardlyof the sewing mechanism so that the pins 34 are dis engaged therefrombefore the seam is started.

During the sewing of the seam the carrier is guided by the engagement ofpins 56 and 58 mounted on the upper clamping plate in cam grooves 60 and61 formed in a block 62 secured to the frame of the machine, these camgrooves being constructed to impart the proper angular movements to thework carrier to cause the needle to operate along a line substantiallyparallel with the reversely curved back edges of the quarters secured inthe carrier.

As the carrier approaches the sewing mechanism a block 64 mounted on theupper clamping plate engages a roll 66 carried by a vertical movable rod68 and lifts the rod. The rod 68 controls. through certain connections,the mechanism for swinging the left hand arm of the lever 18 rearwardlyto engage the clutch for connecting the pulley 10 with the shaft 8, thismechanism being thrown into operation by the vertical movement of therod. The

lever 18 is held in position during the sewing operation by theengagement of the latch 22 with the shoulder 24. During the sewingoperation the work is fed by the action of the feed dog 6 and thecarrier is advanced by the action of the feed belt 50 and by the actionof feed rolls 7 0 and 72 which are mounted below the table 32 andproject slightly above the table so as to engage frictionally the lowerclamping plate. hen the seam has been completed, the latch 22 isdisengaged from the shoulder 24 allowing the left hand arm of the lever18 to be swung forwardly by its actuating spring to disengage thedriving clutch for the shaft 8 by the engagement of a pin 74. carried bythe upper clamping plate of the carrier with the rear end of the latch.

The sewing mechanism is preferably stopped with the needle in the workadjacent the lower edge of the quarters, as shown in Fig. 2, and thepart of the work carrier which is then at the left continues to beadvanced by the feed rolls 70 and 72 thereby swinging the carrier. aboutthe needle as a fulcrum into substanti ally the position of the carrierB, so that when the carrier finally comes to rest it will be out of theway of the succeeding carrier. To permit this movement of the carrierthe rear portion of the right hand wall of the groove 61 is formed on alever 7 6 pivoted at 78 on the block 62. As the left hand arm of thelever 18 is swung forwardly upon stopping the sewing mechanism, thelever 76 is lifted to disengage this part of the wall of the cam groove61 from the pins 56 and 58 by the engagement of the lever 18 with aprojection 80 on the lever 76. i

As the sewing mechanism is started, the carrier containing the parts ofan upper upon which the sewing operation has just been completed andwhich then occupies the position of the carrier B, Fig. 2, is releasedby the disengagement of the needle from the material, and the threadbetween the work carried respectively by this carrier and the succeedingcarrier is severed by a thread severing mechanism. The latter carrier isthen fed rearwardly first by the action of feed roll 72 and then by theaction of feed rolls 82 mounted below the table 32 and projectingupwardly through slots in the table so as to engage frictionally thelower clamping plate, similarly arranged anti-friction rolls 84: and 86being provided to enable the carrier to be fed readily. This brings thelatter carrier into substantially the position of the carrier C, Fig. 2,the carrier stopping at this point because of the fact that it iscarried out of the range of action of the feed rolls 82.

During the movement of a carrier from the position of the carrier to theposition of the carrier B, and the movement of another carrier from theposition of the carrier B to the position of the carrier C, the thirdcarrier, which occupied the position of the carrier C, is carriedforwardly into work receiving position. The mechanism for thus actuatingthe third carrier is fully described in the Mayo application referred toabove and need not be described in the present application.

After a carrier starts to move from the position of the carrier B awayfrom the sewing mechanism, and after a seam is started .in the parts ofan upper secured in the succeeding carrier, the thread extending "etweenthese parts and the parts secured in the preceding carrier is severedautomaticat ly. The mechanism for severing the thread comprises a lever88 secured to one end of a rock shaft 90 and a thread cutting knife 92mounted on the lever. The rock shaft 90 is mounted to turn in a bearingin a support 94 secured to the lower end of a rod 96 which is supportedat its upper end to swing in any direction by a universal joint 97. Thethread cutting knife is thus supported so that it may be moved forwardlyand rearwardly and laterally of the machine. The rock shaft 90 is actedupon by a coiled spring 98 which tends to turn the shaft in adirect-ionto retract the thread cutting knife. The rod 96 lid is actedupon by a coiled spring which tends to swing the same and the threadcutting knife forwardly or opposite to the feed and toward the right,Fig. 1, and maintains the knife normally in the position shown in Fig.7, the movement of the support 9 1 and the knife, toward the right underthe action of the spring being limited by the engagement of a pin 102mounted on the support with a ledge 10st formed on a bracket 106 securedto the frame, and their forward movement being limited by the engagementof the pin with a shoulder 108 located adjacent the forward end of saidledge.

As one carrier is carried away from the sewing mechanism after thecompletion of a scam in the parts of an upper carried there by, andafter a seam is started in the parts carried by the succeeding carrier,the thread cutting knife is moved rearwardly with the carriers and tothe left by the movement of the second carrier into position to engagethe thread between the two sets of upper parts carried by the respectivecarriers. and the. knife lever 88 is then rapidly oscillated to causethe knife to sever the thread. The knife is moved rearwardly by thecarriers at the proper time by the engagement of a pin 110 mounted oneach of the carriers with a latch 112 pivoted at 114 on the support 9st.During the rearward movement thus imparted to the support, the supportis moved to the left by the engagement of the pin 102 with a switch cam116 pivoted at 118 on the bracket 106. The switch cam is normally heldby a spring 120 in the inclined position shown in 7 and 8 with the freeend thereof in engagement with the ledge 10 1. When in this position asthe support 94 is moved rearwardly the pin 102 engages and is carriedalong the face of the switch cam and the support is thereby moved to theright in F ig. 7 or left in Fig. 2. This movement of the support carriesthe knife into the position shown in Fig. 8. As the pin 102 passesbeyond the switch cam the spring 100 moves the support to the left inFig. 8 and the latch 112 is then swung on its axis to disengage the samefrom the pin 110 by the engagement with the latch of a pin 122 securedin the bracket 106. The spring 100 then moves the support 91 forwardlyto its normal position. the switch cam 116 yielding and allowing the pin102 to pass.

The knife lever 88 is actuated to oscillate the knife by means of a pin124 formed on a bracket secured to the needle bar and engaging in a slot120 in the knife lever. The knife lever, when the support 9% is in itsnormal position, is locate-c. in the angular position shown in Fig. 1and in full lines in Fig 5, the slot 120 then lying substantiallyparallel with the direction of reciprocation of the pin 12 1. lVith thelever in this position, the pin 12 1 reciprocates idly in the slot 126.

The movement of the support 94 to the left, however, causes the knifelever to assume a position in which the slot lies at an angle to thedirection of movement of the pin 12 1 so that the lever is thenoscillated by the recip ried by the preceding carrier. The knife thusmakes several cutting strokes at the same point in the thread and theseverance of the thread is practically insured.

The driving mechanism for the disk 14:, the belt 50 and the feed rolls70, 7 2, and 82 is lv described in the above Mayo applicam, and adescription of the same is unnecesfor an understanding of the presentinmtson. The disk 4/1- is driven intermittently in the manner abovedescribed. The feed belt 50 and the feed rolls T0, 7 2, and 82 aredriven continuon. y through suitable connections from the main orivingshaft 16.

Hm ilained the nature and object of I and having specifically dem chineen'ibodying the invenform, what claimed is:

l. A machine for sewing together sections o? sheet terial having, incombination, stitch 'l'ornnng mechanism, a thread cutting "ice,mechanism for actuating the cutting "'cc, and a movable work carrierarranged y the cutting device with it from in-. operative to operativeposition with relation to the thread to be severed and to throw theactuating mechanism into operation during in movement wi h the carrier.

2. A niachine for sew' ig together sections of sheet material havin incombination, st g-ch forming mecl'ianism, a thread cutting devicemovable in the direction of the feed, and a work carrier bodilyn'lovable with the work during the formation of a series of stitches anged to carry the cutting device in the direction of the feed while saiddevice is operated to cut the thread.

3. A machine for sewing together sections of sheet material having, incombination, stitch forming mechanism, a series of movable work carrierseach provided with means for embracing a plurality of sections of sheetmaterial and holding them in superposed relation, means for moving thecarriers successively past the stitch forming mechanism, a threadcutting device, and means on each of the carriers for controlling theoperation of the thread cutting device.

4-. A machine for sewing together sections of sheet material having, incombination, stitch forming mechanism, a series of unconnected carrierseach provided with means for retaining the plurality of sections ofsheet material in superposed relation, means for moving the carrierssuccessively past the stitch forming mechanism, a thread cutter, andmeans on each carrier for throwing the cutter into operation to cut thethread between that carrier and the next preceding carrier.

5. A machine for sewing together sections of sheet material having, incombination, stitch forming mechanism, a series of work carriers, athread cutter for cutting the thread between the carriers, and means forthrowing the cutter into and out of opera tion and for giving it severalthread cutting movements in each cutting operation.

6. A machine for sewing together sections of sheet material having, incombination, stitch forming mechanism. a work carrier, means for movingthe work carrier pastthe stitch forming mechanism, a thread cutter, andmeans for bringing the cutter into cutting relation to the thread andfor giving it several cutting movements in each cutting operation.

7. A machine for sewing together sections of sheet material having, incombination, stitch forming mechanism, a series of work carriers, meansfor moving them in succession past the stitch forming mechanism, athread cutter for cutting the thread between the carriers, and means forrendering the cutter active on the thread and for giving it severalthread cutting movements in each cutting operation. 7

8. A machine for sewing together sections of sheet material having, incombination, stitch forming mechanism, a thread cutting device, amovable work carrier arranged to carry the thread cutting device withthe work during the cutting operation of the cutter on the thread.

9. A machine for sewing together sections of sheet material having, incombination, stitch forming mechanism, a series of movable carriers forsuch material, means for moving the carriers in succession past thestitch forming mechanism, a device for severing the thread between theparts of the work carried by successive carriers, and means on thecarriers for moving the thread severing device in the direction of feedwith the carriers and for shifting said device transversely of thedirection of feed to throw the same into operation.

10. A machine for sewing together sections of sheet material having, incombination, stitch forming mechanism, a series of movable carriers forsuch material, means for moving the carriers in succession past thestitch forming mechanism, a device for severing the thread between theparts of the work carried by successive carriers, means on the carriersfor moving the thread severing device in the direction of feed with thecarriers, and mechanism for actuating said destitch forming mechanism, amovable carrier for such material, a thread severing device, a movablesupport for the thread severing device, means on the carrier for movingsaid device in the direction of feed, a switch for shifting said devicelaterally during this movement, arranged to allow the return of saiddevice after a predetermined movement thereof, mechanism fordisconnecting said device from said means, and a spring for returningsaid device to its initial position.

12. A sewing machine having, in combination, stitch forming mechanism, athread severing device movable in the direction of feed and in adirection transverse thereto in a plane substantially parallel to theplane of the work, mechanism for moving the thread severing device inthe direction of feed with the Work, and means for moving said device ina direction transverse to the direction of feed in a plane substantiallyparallel to the plane of the work during its movement in the directionof feed to throw the same into operation, to cut the thread 13. A sewingmachine having, in combination, stitch forming mechanism, a threadcutting knife, a pivoted knife carrier, a reciprocating member, a pinmounted on said member, a slot formed in the knife carrier in which saidpin engages, means normally maintaining the knife carrier in positionwith the slot parallel to the direction of reciprocation of said pin,and means for moving the carrier to locate the slot at an angle to thedirection of reciprocation of said pin, and thereby cause the pin tooscillate the knife carrier and knife.

14. A sewing machine having, in combination, stitch forming mechanism, athread severing knife, a pivoted knife carrier, a reciprocating member,a pin mounted on said member, a slot formed in the knife carrier andarranged to receive the pin, a support movable in a direction transverseto the direction of feed on which the knife carrier is pivoted, meansfor maintaining the knife carrier in position with the slotsubstantially parallel to the direction of reciprocation of the pin, andmeans for moving the knife carrier in a direction transverse to thedirection of feed to place the slot at an angle to the direction ofreciprocation of the pin. and thereby cause the oscillation of the knifecarrier and the knife and to locate the knife in position to sever thethread.

15. A machine for sewing together sections of sheet material having, incombination, stitch forming mechanism, a movable carrier for suchmaterial, a thread severing device, a movable support for said device,means on the carrier for moving the support to carry said device in thedirection of feed, and a switch for shifting the support during themovement of the support in the direction of feed to move said device ina direction transverse to the direction of feed.

16. A sewing machine having, in combination, stitch forming mechanism, athread severing device, means for moving said device in the direction offeed with the work, and means for imparting an additional movement tosaid device to sever the thread during the movement of said device inthe direction of feed.

17. A machine for sewing together sections of sheet material having, incombination, stitch forming mechanism, a movable carrier for suchmaterial, a thread severing device, a movable support for said device,means on the carrier for moving the support with the carrier, and aswitch for guiding the support during its movement.

18. A machine for sewing together sections of sheet material having, incombination, stitch forming mechanism, a thread cutting device, a workcarrier provided with means for holding thereon a plurality of suchsections and arranged to carry the cutting de vice in the direction ofthe feed while said device is operated to cut the thread, said carrierbeing bodily movable with the work during the formation of a series ofstitches.

19. A sewing machine having, in combination, stitch forming mechanism, athread cutting device and a movable work carrier arranged to carry thecutting device with the work while said device is operating to cut thethread, said carrier being bodily movable with the work during theformation of a series of stitches. I

JOHN M. BENJAMIN.

